1. Field of the Invention
The invention relates to linkages for seats having inclination adjustment, in particular for vehicle seats.
2. Summary of the prior art
German Gebauchsmuster No. 7,031,179 discloses linkages in which one link part is fixedly mounted on a seat part and another link part is pivotable in accordance with the inclination, the parts being interconnected by a pivot pin. An adjustment and fixing arrangement is provided for both linkage parts in which one link part is secured to an internal annular hear and the oher link part is secured to a spur gear meshing with it, the addendum circle of the spur gear being smaller by the height of one tooth than the dedendum circle of the internal annulus gear. The link part associated with the seat part is mounted eccentrically on the pivot axis formed as a pin, the eccentricity corresponding substantially to the diameter of the pin and of which the ratio of thickness to diameter is relatively small. The eccentricity of this eccentric, rotatable by means of a hand grip, corresponds substantially to the difference between the dedendum circle of the internal annulus gear on the one hand and the addendum of the spur gear on the other hand and is so dimensioned that a self-jamming between the internal annulus gear and the spur wheel is produced. The internal free space of the internal annulus gear receives a bridging member which provides an integral bearing for the eccentric. The link part supported about the pivot axis by the gear parts is thus surrounded with a gear part of the other link and is integral with the corresponding gear part opposite to the side of the pivot axis and carrying a bearing housing.
The linkage has several disadvantages. A particular disadvantage lies in the exceptionally costly manufacture of the individual constructional parts, in particular the two link parts, as well as the eccentric pin.
An object of the present invention is therefore so to produce a linkage that the cost of the individual constructional parts is reduced to a minimum.